these 3 derivations will be built:
  /nix/store/h23w1ymmqd3mh6c3civigv3vxs6ns9dz-source.drv
  /nix/store/fmf1lks61iibhdx3f24vlm91jl8ysjij-collie-1.14.1.drv
  /nix/store/m371ayaszfbyvy9swi8azfs0dmax6mg9-check-collie.drv